My computer acted as if windows was just installed... 4 months after it was.

[Opencircuit74]

So, this morning I woke up my computer and it was all normal, with everything I had installed over the past few months on it. When I got back from school approx 12 hours later, Microsoft edge acted like windows was just installed, telling me that it is better than chrome (which it isn't in my opinion). Google chrome was not in my taskbar, and when I opened it up it acted as if it was the first time. All of my files are now gone from the desktop, and I am worried that I had lost a lot of information that I worked hard to get. In addition to this, my trash can was empty, but it was full earlier. Also, my SSD now only has 18gigs left on it compared to the 20+ it had this morning. Steam and other apps acted as if it was their first time opening. The odd thing is though, my system says it has been running for three days. Does anyone know what's going on, and if so, could someone help me get my data back?

[Opencircuit74]

So it turns out, someone else used the computer that I was unaware of and stayed signed in their account. Everything's back to the way it was.